No hot water, intermittent when air temp drops?
Valiant thermostat , BMU-Err ?
Vaillant eco plus 531 boiler?
Vaillant Thermocompact Fault?
how to fix water pressure its down at bottom of grey part?
Water dripping from opening at top of pump?
Vaillant 828E - no hot water?
Vaillant igniting issue ( domestic ) not CH?
how do I rectify the fault as detailed below?